Method for producing chemicals, especially amalgamated printing plates



METHOD FOR PRODUCING CHEMICALS, ESPECIALLY AMALGAMATED PRINTING PLATES Filed sept. 25. 1935 Patented Sept. 14. 1937 ESPECIALLY PLATES METHOD FonfffinonUCING CHEMICALS, AMALGAMATED PRINTING Heinrich Renck, Hamburg, Germany Application September 25, 1935, Serial No. 42,0595' In Gnermany May 15, 1935 2 claims. (ci. il-41.5)

The invention consists in an improvement of the'well-know'n processes for producing ink-repellent portions on a printing plate. The known processes employ metallic mercury mixture,

5 preferably giycerine to which metallic mercury is added. The mercury separating from the glycerine forms on the portions of the printing plate which must be ink-repellent a soft layer of mercury, i. e. a soft amalgam which, during the printing, is very soon squeezed out so that only avery limited number of prints can be made.

The invention has for its object to form a lsolid amalgam layer on the ink-repellent portions of the printing plate and with this object in view the glycerine is saturated with a mixture of ground nitrate of silver and ground nitrate of mercury.

These mixtures are added in the following proportionst-To 2 litres of giyeerine 10 grams of ground nitrate of silver and 100 grams of nitrate of mercury are added.

The preparation is applied on to the denickeled portions of the printing plate so that the nitrate of silver and the nitrate of mercury deposit on these portions and form on the same a solid amalgam layer which has an ink-repellentl elect during the printing.

A printing plate is produced in the following manner by the process according to the invention:-

A brass coated iron plate is nickel-plated and' the printing or design to be reproduced is transferred on to this nickel surface. The nickel is thenl removed from the portions which are not covered'by the transfer. `The process up to this point d lsnot diier from the known processes.

According to the invention nitrate of silver and nitrate of `mercury are rubbed to a powder and dissolved in glycerine to saturation, where- 5 upon this saturated glycerine is applied on the denickeled portions of the plate and here forms a solid amalgam layer.

The accompanying drawing shows the plate in the three different stages of its production. 10

Fig. 1 shows the iron plate I.with the brass coating 2 and the nickel coating 3 with the transfer 4 applied thereon.

Fig. 2 shows the plate after the removal of the nickel coating 3 at the portions not covered 15 by the transfer 4.

Fig. 3 shows .the plate with solid amalgam layer 5 in the denickeled portions of the plate.

1. Method of producing an ink repellent amal- 20 gam layer on certain portions of a printing plate, consisting in nickel-plating an iron plate coated with brass, applying `the picture on the nickelplated surface, removing the nickel-plating at the portions not covered by the picture, grinding 25 together to a powder nitrate of silver and nitrate of mercury, dissolving this mixture in glycerne to saturation and applying this saturated solution on the denickeled portions of the plate.

2. In a method as specie'd in claim 1, in which 30 the saturated glycerine solution consists of 10 grams of nitrate of silver and 100 grams of nitrate of mercury dissolved in 2 litres of glycerine.

HEINRICH RENCK. 

